The concept of intercultural communication competence (ICC) has become a leading foundation in second-language learning, particularly in multilingual and multicultural classrooms in the United States. Since TESOL programs are becoming increasingly responsive to diverse student populations, a teacher's capacity to promote meaningful cross-cultural awareness has become a significant determinant of learners' engagement, language proficiency, and overall communicative competence. The article explores the conceptual background and pedagogical and practical issues of ICC in second-language teaching and presents ICC as a vital component of modern-day TESOL programs in the United States. Using the frameworks of Byram ICC, the Process Model of Deardorff and the most recent sociocultural studies, the article reveals how ICC contributes to the achievement of culturally inclusive pedagogy, teacher-student relationships, and pragmatic competence of learners. The research also assesses the current state of ICC integration in U.S. TESOL programs, its strengths, gaps, and the structural issues of teacher-training institutions. It also examines social changes, such as greater linguistic diversity, global mobility, and equity-based educational requirements, which call for a more robust embedding of ICC models in TESOL preparation. Pragmatic suggestions include redesigning the curriculum, planning assessments, implementing experiential learning in the community, and providing focused professional development. The article ends with a conception of a progressive model for integrating ICC into TESOL programs, focusing on sustainable, quantifiable, and pedagogically applicable aspects. The results highlight that intercultural competence is no longer a pleasant add-on but a legacy of effective second-language teaching in the American context.